IUSN - Leather

This International Standard specifies a chromatographic method to determine the amount of middle-chain chlorinated paraffins (MCCP) C14-C17 in processed and unprocessed leather.

This standard specifies a Chromatographic method for the determination of short-chain chlorinated paraffins (SCCP) in leather

This document gives recommended values and related test methods for apparel leather, excluding furs.
It also specifies the sampling and conditioning procedures of laboratory samples.

This document specifies a method of determining the dimensional change (shrinkage) of leathers
caused by ageing. It is applicable to all leathers.

This document specifies a method for the determination of free formaldehyde, which is released under
dynamic conditions when the sample is heated in an inert dry atmosphere, in process auxiliaries for
leather. The analytical result obtained according to this procedure is expressed in milligrams per
kilogram (mg/kg) sample.

This document specifies a method for the determination of free and released formaldehyde in leathers.
This method, based on high-performance liquid chromatography (HPLC), is selective and not sensitive
to coloured extracts and is intended to be used for precise quantification of formaldehyde.
The formaldehyde content is taken to be the quantity of free formaldehyde and formaldehyde extracted
through hydrolysis contained in a water extract from the leather under standard conditions of use.

This document specifies a method for determining the use of certain azo colourants which can release
certain aromatic amines.

This document specifies a test method by acetonitrile solvent extraction for the determination
of the total content (solvent extractible) of the following preservative agents in leather by liquid
chromatography:
— 2-(thiocyanomethylthio)-benzothiazole (TCMTB);
— 4-chloro-3-methylphenol (PCMC);
— 2-phenylphenol (OPP);
— 2-octylisothiazol-3(2H)-one (OIT);
This method can also be used to determine breakdown products of these preservative agents, which
protect leather from microbiological attack.

This document specifies a test method by artificial perspiration solution aqueous extraction for the
determination of the aqueous extractable content of the following preservative agents in leather by
liquid chromatography:
— 2-(thiocyanomethylthio)-benzothiazole (TCMTB);
— 4-chloro-3-methylphenol (PCMC);
— 2-phenylphenol (OPP);
— 2-octylisothiazol-3(2H)-one (OIT);
This method can also be used to determine breakdown products of these preservative agents, which
protect leather from microbiological attack.

This document specifies a test method to determine the degree and rate of aerobic biodegradation
of hides and skins of different animal origin, whether they are tanned or not, through the indirect
determination of CO2 produced by the degradation of collagen.
The test material is exposed to an inoculum (activated sludge from tannery wastewater) in an aqueous
medium. If there is not a tannery nearby then urban wastewater can be used as the inoculum.
The conditions established in this document correspond to optimum laboratory conditions to achieve
the maximum level of biodegradation. However, they might not necessarily correspond to the optimum
conditions or maximum level of biodegradation in the natural medium.
In general, the experimental procedure covers the determination of the degradation degree and
rate of the material under controlled conditions, which allows the analysis of the evolved carbon
dioxide produced throughout the test. For this purpose, the testing equipment complies with strict
requirements with regard to flow, temperature and agitation control.
This method applies to the following materials:
— natural polymers of animal stroma (animal tissue/skins);
— animal hides and skins tanned (leather) using organic or inorganic tanning agents;
— leathers that, under testing conditions, do not inhibit the activity of microorganisms present in the
inoculum.

This document specifies a method for determining the tensile strength, elongation at a specified load
and elongation at maximum force of leather. It is applicable to all types of leather.

EN-ISO 14080 specifies a test method for the determination of tanning agents through filtration of all vegetable and synthetic tanning products

EN-ISO 17131 specifies a method using microscopy to identify leather and distinguish it from other materials. The method is not applicable for identifying specific leathers (e.g. sheep leather).

This document specifies a method of determining the abrasion resistance of leather using a Taber® apparatus

This document specifies a method for determining the stitch tear resistance of leather. It can be used on
all leathers but is particularly suitable for leathers over 1,2 mm in thickness.

This document specifies a method for determining alkylphenols (nonylphenol and octylphenol)
and alkylphenol ethoxylates (nonylphenol ethoxylate and octylphenol ethoxylate) in leather and
process auxiliaries. The analysis is based on high-performance liquid chromatography (HPLC) or gas
chromatography-mass spectrometry (GC-MS).
The analysis of the alkylphenol ethoxylate is made by cleaving the alkylphenol ethoxylate and
measuring the released alkylphenol.
NOTE ISO 18218-1 and this document use different solvents for the extraction of the ethoxylated
alkylphenols from leather. Consequently, the two analytical methods are expected to give similar trends but not
necessarily the same absolute result for the ethoxylated alkylphenol content in leather.

This document specifies a method for determining the resistance of all forms of leather to visible soiling
through repeated contact with soiled objects. It provides a physical pretreatment routine for leathers
that may be vulnerable to loss of soiling resistance while in service, prior to conducting further tests
such as cleaning.

This document is a reference document to support  the correct measurement of the colour of  finished  leather  by  instrumental  means.  The  document  describes  general  concepts of colour measurement adapted to leather and the calculation of differences in colour. This document defines the following:
a) the use of D65 as the standard light source for the leather industry.
b) the use of D65 light source 10º as standard conditions for colour matching, for the definition of daylight simulators, and as the
reference light source for metamerics analysis.
c) the use of CIE DE2000 as the colour difference formula

This document specifies a method for the determination of extractable metals in leather using extraction
with an acid artificial-perspiration solution and subsequent determination with inductively coupled
plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICPMS),
atomic absorption spectrometry (AAS) or spectrometry of atomic fluorescence (SFA).
This method determines extractable metals in leather; it is not compound-specific or specific to the
oxidation state of the metals. This method is especially suitable for determining the extractable
chromium in chromium-tanned leathers.

This document specifies a method for the determination of the total metal content in leather using
digestion of the leather and subsequent determination with inductively coupled plasma optical emission
spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption
spectrometry (AAS) or spectrometry of atomic fluorescence (SFA).
This method determines the total metal content in leather; it is not compound-specific or specific to the
oxidation state of the metals.
The method is applicable for determining the following metals:
Aluminium (Al) Copper (Cu) Potassium (K) Antimony (Sb) Iron (Fe) Selenium (Se)
Arsenic (As) Lead (Pb) Silicon (Si) Barium (Ba) Magnesium (Mg) Sodium (Na)
Cadmium (Cd) Manganese (Mn) Tin (Sn) Calcium (Ca) Mercury (Hg) Titanium (Ti)
Chromium (Cr) (except chromium-tanned leathers) Molybdenum (Mo) Zinc (Zn)
Cobalt (Co) Nickel (Ni) Zirconium (Zr)
This method is also suitable for determining Boron (B) in leather.
In the case of chromium-tanned leathers, it is often more relevant to use ISO 5398-1[1], ISO 5398-2[2],
ISO 5398-3[3] or ISO 5398-4 [4].
Interlaboratory test results and the quantification limits possible with ICP-OES are given in Table A.1
and Table A.2 of Annex A.

This document specifies a method for the determination of free and released formaldehyde in leathers.
This method, based on colorimetric analysis, is not intended to be used for a precise quantification of
formaldehyde.
The formaldehyde content is taken to be the quantity of free-formaldehyde and formaldehyde extracted
through hydrolysis contained in a water extract from the leather under standard conditions.
This process is not absolutely selective for formaldehyde. Other compounds such as extracted dyes
could interfere at 412 nm.

This document describes a method for the determination of chromium in aqueous solution obtained
from leather. This is an analysis for total chromium in leather; it is not compound specific or specific to
its oxidation state.
This method describes the determination of chromium by inductively coupled plasma (ICP) and is
applicable to leathers which are expected to have chromic oxide contents in excess of 1 mg/kg. Two
techniques for the preparation of the solution to be analysed are included. In the event of dispute, the
wet oxidation technique is intended to be used.

This document specifies a test method for detection and quantification of extractable neutral, ionic,
long, medium and short chain perfluorinated and poly-fluorinated substances in leather and coated
leather.
This document, taking into account the three-dimensional distribution of the fibres within leather,
makes the evaluation of the perfluorinated and poly-fluorinated substances with respect to the mass.
Classes of regulated compounds listed in Annex A, Table A.1, include acids, telomers, sulfonates and
sulphonamide alcohols. Classes of other non-regulated compounds that can be determined by this
document are defined in Annex B, Table B.1.

This document specifies a method for determining the behaviour of the surface of a leather on rubbing
with a wool felt.
It is applicable to leathers of all kinds.

This document describes a method for the determination of chromium in aqueous solution obtained
from leather. This is an analysis for total chromium in leather; it is not compound specific or specific to
its oxidation state.
This method describes the determination of chromium by atomic absorption spectrometry and is
applicable to leathers which are expected to have chromic oxide contents in excess of 5 mg/kg. Two
techniques for the preparation of the solution to be analysed are included. In the case of disputes, the
wet oxidation technique is to be used.

This document specifies a method of determination of water-soluble matter, water-soluble inorganic
matter and water-soluble organic matter.
It is applicable to all leather types. The result obtained by this analysis depends on factors such as:
— the degree to which the leather is ground;
— the extraction temperature;
— the extraction period;
— the ratio of leather to water.
To obtain comparable results, it is consequently imperative that test conditions be accurately
reproduced.
In all cases, any ammonium salts in the filtrate are included as part of the water-soluble matter and
are then decomposed on ignition. Thus they contribute towards the result for water-soluble organic
substances. The concentration of the ammonium salts can be determined in the filtrate separately if
required.

This document specifies a method for the determination of the substances in leather which are soluble
in dichloromethane. This method is applicable to all types of leather.
Not all fatty and similar substances can be extracted from leather with organic solvents; they may be
in part soluble and partly bound to the leather. On the other hand, the solvent can dissolve non-fatty
substances, for example sulfur and impregnants, both of which cause difficulty in the determination of
the acid value and saponification value of the fat.
This document includes two techniques for extraction of the fatty substances: 1) extraction using the
Soxhlet apparatus; and 2) extraction using a pressurized extraction system.
As the extraction is frequently done in conjunction with determination of the free fatty acid content of
the leather, a suitable procedure for determination of the free fatty acids extracted by this method is
included.
The apparatus and technique described in this method are also suitable for the extraction by solvents
other than dichloromethane (although the temperature conditions may need to be varied for high
pressure extraction).

This document describes a method for the determination of chromium in aqueous solution obtained
from leather. This is an analysis for total chromium in leather; it is not compound specific or specific to
its oxidation state.
This method describes the determination of chrome by iodometric titration and is to be applicable to
chromium-tanned leathers which are expected to have chromic oxide contents in excess of 0,3 %. Two
different methods are described as alternatives for obtaining chromium in a suitable solution. It is
appropriate to use either method.

This document specifies a method for determining the pH value and the difference figure of an aqueous
leather extract. It is applicable to all types of leather.

This document specifies a method for determining the colour fastness to saliva of all kinds of leathers,
independent of the colouring procedure applied.
The method uses an artificial saliva solution to simulate whether colouring materials can migrate from
leather to the mouth or to the mucous membranes.

This document specifies a method for determining the repellency of leather to surface wetting. It is
applicable to all leathers intended for use in clothing. The method does not determine the resistance of
leather to water penetration.

This document gives guidelines to apply the available chemical test methods for leather. This
information can be used by those involved in setting specifications for leather, especially for those
parameters relating to restricted chemical substances.
Lists of restricted chemicals contain many substances that are not relevant to the leather industry.
Those chemical substances that are not mentioned in this document do not need to be determined, thus
avoiding unnecessary analytical costs.

The scope of this standard is to calculate the Product Carbon Footprint (PCF) of leather as defined in EN 15987 and sold in the semi-processed state or ready to be shipped for use in consumer articles manufacturing processes.

This document specifies a method for determining the apparent density and the mass per unit area of
leather. It is applicable to all leathers.

This document specifies a method for determining chromium(VI) in solutions leached from leather
under defined conditions. The method described is suitable to quantify the chromium(VI) content in
leathers down to 3 mg/kg.
This document is applicable to all leather types.
The results obtained from this method are strictly dependent on the extraction conditions. Results
obtained by using other extraction procedures (extraction solution, pH, extraction time, etc.) are not
comparable with the results produced by the procedure described in this document.
If a leather sample is tested with both ISO 17075-1 and this document, the results obtained with this
document are considered as the reference. The advantage of the method described in this document is
that there are no interferences from the colour of the extract. Nevertheless, interlaboratory trials do
not show significant differences (see Annex D) and the results are comparable between both methods.

This document specifies a method for determining the wet or dry flex resistance of leather and finishes
applied to leather. It is applicable to all types of flexible leather below 3,0 mm in thickness.

This document specifies the location of a laboratory sample within a piece of leather and the method of
labelling and marking the laboratory samples for future identification.
It is applicable to all types of leather derived from mammals irrespective of the tanning used.
It is not applicable to leathers derived from birds, fish, reptiles or furs.

This document specifies two methods for determining the heat resistance of patent leather.
Method A makes use of a modified lastometer, while Method B uses the “Zwik” apparatus. Both methods
are applicable to patent leathers for all end uses.

This document specifies a method for determining the cold crack temperature of surface coatings applied
to leather. It is applicable to all leathers which have a surface coating and which can be easily flexed.

This standard specifies a method for testing critical chemicals in leather

This document specifies how to prepare a test sample of leather for chemical analysis. The test sample
can be either ground or cut into small pieces. Unless specified in this document, the method to be used
depends on the size of leather sample available for testing.

This International Standard provides a method for the measurement of the surface of leather or leather
parts by the use of electronic measuring machines.
It applies to the measurement of leather (or leather parts) fulfilling the following requirements:
— flexible leather, finished or unfinished, dry or wet leather;
— flexibility: such to allow full distension on the measuring line/surface.
NOTE For tanned and pressed wet leather, the parties involved agree on the conditioning type. In case of
dispute, leather is to be conditioned according to the reference standard conditions in ISO 2419.

This International Standard specifies a method to determine the amount of N-methyl-2-pyrrolidone
(NMP) in leather and leather components.
This method may also be used for the determination of N-ethyl-2-pyrrolidone (NEP) in leather.

This International Standard specifies a test method for the determination of chromium (VI) content in
chromium tanning agents. The results give information about the reductive potential of the chromium
tanning agent.

This International Standard specifies a method for determining the water absorption of leather under static conditions.
The method is applicable to all leather, particularly heavy leather

This standard specifies a method for determining the tear strength of leather using a double edged tear.
The method is sometimes described as the Baumann tear. It is applicable to all types of leather.

This International Standard specifies a method for determining the water vapour absorption of leather. The method
is applicable for all leathers but is particularly relevant for leathers intended for footwear uppers and linings.

This International Standard specifies a method for determining the thickness of leather. The method is
applicable to all types of leather of any tannage. The measurement is valid for both the whole leather
and a test sample.

This International Standard specifies a method for determining the extension set of leather. It is intended for use
on upholstery leather but is applicable to all flexible leathers.

This European Standard defines the requirements that are necessary to confer the origin of leather
production based on the principle of the last substantial transformation according to Non-Preferential
Rules of Origin.
This European Standard applies to leather only and it applies also to leather with hair. Furs are
excluded.
The country of origin of raw hides and skins isn’t relevant for the application of this standard.